AJP - Renal Physiology, Vol 246, Issue 1 101-F104, Copyright © 1984 by American Physiological Society
Identification of actin-binding protein and villin in toad bladder epithelia
D. A. Ausiello, H. L. Corwin and J. H. Hartwig
Two actin-modulating proteins, actin-binding protein and villin, have been
identified and functionally characterized in toad bladder epithelial cells.
A 270-kdalton protein from bladder epithelial extracts 1) cross-reacts with
antibodies to purified toad oocyte or rabbit macrophage actin-binding
protein and comigrates with these proteins on gel electrophoresis, 2)
contains all of the actin filament cross-linking activity found in
epithelial cell extracts, and 3) its activity is calcium insensitive. A
95-kdalton protein from the same extracts 1) cross-reacts with antibodies
to purified toad oocyte villin and comigrates with purified villin from the
oocyte and chicken intestine on polyacrylamide gels, and 2) is capable of
decreasing the viscosity of actin solutions only in the presence of
calcium. These proteins offer potential sites for calcium-dependent and
-independent regulation of toad bladder epithelial cell structure.
